Inlet for chromatographs and the like



March 26, 1968 c. B. MCKINNEY ET AL 3,374,660

INLET FOR CHROMATOGRAPHS AND THE LIKE Filed June 28, 1966 INVENTORS.

United States Patent 3,374,660 INLET FOR CHROMATOGRAPHS AND THE LIKECarlton B. McKinney, Los Angeles, and William M. Sheppard, Whittier,Calif., assignors to Hamilton Company, Whittier, Califi, a corporationof California Filed June 28, 1966, Ser. No. 561,085 19 Claims. (Cl.73-23.1)

This invention relates generally to chromatography and the like andrelates more particularly to inlets for chromatographs.

While the invention ha particular utility in connection with inlet forgas chromatographs, andis shown and described in such connection, it isto be understood that its utility is not confined thereto.

As is well known in the art there are certain problems involved in theprovision of inlets for chromatographs, one of said problems is bandspreading which occurs in such gas chromatographs of which I am awareand it is an object of the invention to provide an inlet wherein suchband spreading is prevented or substantially eliminated and separationby the column is enhanced.

Still another object of the invention is to provide an inlet forchromatographs having means for applying a suitable compression force orpressure on the septum at all times. A further object of the inventionis to provide an inlet for chromatographs wherein the septum sealsinstantly when the needle is withdrawn thus preventing back-flow of thesample and substantially improving quantitative injection. A furtherobject is to provide an inlet of this character wherein needle cuts andextrusion of pieces of the septum into the inlet are minimized oreliminated. A still further object is to provide an instrument of thischaracter wherein the problem of absorption or reaction of sensitivesamples on metal surfaces or the like is eliminated. Another object ofthe invention is to provide an instrument of this character.

A still further object of the invention is to provide an inlethavingmeans for guiding the needle into the instrument, through theseptum and into the carrier fluid passage without hang-up. Anotherobject of the invent on is to provide an inlet with which shallowinjection may be made to prevent vaporization of uncontrolled quantitiesof sample from the needle of the sampling syringe. Still another objectis to provide such an instrument having means for preheating the carriergas and keeping it at a uniform temperature. A further object of theinvention is to provide a chromatograph inlet wherein the vaporizingtube may be packed with absorbent or filtering material orsome selectivereactive material to retain or modify some part or component of asample. The vaporizer tube may be packed for on-column injection orpre-column chemistry.

A still further object of the invention is to provide an inlet forchromatographs and the like which may be quickly and accuratelyassembled, wherein the septum may be easily and quickly replaced, andwherein there is easy access to the inner parts for replacement and/orcleaning. This is all possible by reason of the spring loaded retainer.

Broadly the invention concept comprises an inlet for chromatographs andthe like having means defining a fiow passage for a carrier fluid, witha relatively small opening for reception of a small diameter part of aninstrument for introduction into said passage of a sample to beanalyzed, a penetratable septum covering said opening for sealing same,a septum retainer engageable with said septum, and resilient means forresiliently urging the septum retainer against the septum so that saidseptum is under a predetermined and correct pressure.

More particularly the invention provides an inlet for chromatographs andthe like having an outer body of material that provides evendistribution of heat from a heater so as to eliminate cold spots. Theflow passes cleanly to the column through a glass vaporizer tube withoutband spreading voids, the flow path being such as to pre-heat theincoming carrier gas. There is provided high velocity for the pre-heatedgas stream that continuously washes the septum area, the septum beingexposed to material in the inlet is extremely small, being practicallyzero. There is also a unique spring-loaded retainer which permits quickreplacement of septums and allows easy access to the inner parts forreplacement or cleaning and the constant pressure of the spring causesthe septum to instantly seal when the needle is withdrawn.

The characteristics and advantages of the invention are furthersufiiciently referred to in connection with the following detaileddescription of the accompanying drawings which represent one embodiment.After considering this example, skilled persons will understand thatmany variations may be made Without departing from the principlesdisclosed and we contemplate the employment of any structures,arrangements or modes of operation that are properly within the scope ofthe appended claims.

Referring to the drawings, which are for illustrative purposes only:

FIG. 1 is a side elevational view of an inlet embodying the presentinvention attached to a chromatograph;

FIG. 2 is an enlarged longitudinal sectional view through the inlet;

FIG. 3 is an enlarged perspective view of the outer end of the vaporizertube;

FIG. 4 is an enlarged perspective view of the outer end of the liner;

FIG. 5 is a fragmentary, enlarged view of the knob for the septumretainer assembly; and

FIG. 6 is an enlarged sectional view through the vapon'zer tube withpacking therein.

Referring more particularly to FIGS. 1 and 2 there is shown and inletembodying the present invention, said inlet being indicated generally at10, removably attached to a chromotograph, indicated at 12.

The inlet 10 comprises an elongated main body 14 of a metal that is agood heat conductor, aluminum being a metal that meets the requirementssatisfactorily.

Body 14- has a bore or passageway 16 extending longitudinallytherethrough with an internally threaded forward end portion 18, forreception of a threaded part 20 of a column fitting, indicated generallyat 22. This fitting is well known and has a hexagonal head 24 forengagement by a suitable wrench or other tool for turning same. There isalso a nipple 26 extending forwardly from the head 24 and provided withan enlarged externally threaded end portion 228 for screwing into atapped opening in the chromatograph column. A bore 30 extends from theinner or rear end of the fitting and terminates in a shoulder 32intermediate the ends of said fitting, from which a reduced diameterbore 34 extends forwardly and terminates in an enlarged recess fromwhich the passage flares, as at 36.

The main body 14 is square in cross section although it may be of otherconfiguration, and at the rear end said body has a disc-like knob orhead 40 spaced rearwardly of the rear end of the main body 14 andconnected therewith by means of a reduced diameter part 42, the bore 16extending through the head or knob 40 and neck 42.

There is a vaporizer tube 46 defined by a cylindrical wall and having apassage 48 extending longitudinally therethrough, said tube being ofglass which is inactive although any other suitable material may beused. A forward end portion of the vaporizer tube is rather snuglyreceived in the bore 30 of the fitting with the forward end of the tube46 abutting against the shoulder 32 of said fitting, the rear end ofsaid vaporizer tube then being spaced inwardly or forwardly of the rearend of the bore or passage 16, it being noted that the diameter of thebore 34 of the fitting is substantially the same as the passage 48through the vaporizer tube so that there will be a smooth flow of fluidthrough the passage 48 and bore 34.

Vaporizer tube 46 has a substantially smaller external diameter than thediameter of the passage 16 of the body so that there is an annular spacebetween the vaporizer tube and the wall of the body passage 16.

A tubular liner 50 is disposed on the vaponzer tube 46, said liner alsobeing of glass although it may be of any other suitable material. Theoutside diameter of the liner is such as to fit rather snugly in thebore 16 of the body and the diameter of the passage 52 extendinglongitudinally of the liner is greater than the external or outsidediameter of the vaporizer tube to thereby provide an annular space 54which may be termed an annular flow passage between the vaporizer tubeand the liner.

The liner is shorter than the vaporizer tube and is open at the forwardend but is provided with an outer end wall 56 having a small opening 58therethrough which IS 111 alignment with the passage 48 of the vaporizertube. The end wall 56 of the liner abuts against the outer end of thevaporizer tube and in order to provide a fluid connection between thepassage 54 and the passage 48 of the vaporizer tube there are a pair ofdiametrically opposite notches 60 in the rear end of said vaporizer tubeso that fluid may flow from the annular passage 54 through said notchesand into the passage 48 of the vaporizer tube.

Since the liner 50 is shorter than the vaporizer tube the annular spacebetween the vaporizer tube and ad acent wall of passage 16 comprises .anannular chamber 64 between the forward end ofsaid liner and the innerend of the fitting 22, said chamber communicating with the annular flowpassage 54 between the liner and the vaporizer tube.

There is an input fitting 220, similar to the fitting 22, which isscrewed into a laterally arranged tapped bore 66, said input fittingbeing adapted to be connected with a source of carrier fluid underpressure which is supplied to said chamber 64 through passage 22b ofsaid fitting. A seal 68 is provided for the fitting 22a.

A septum 70 is positioned against the outer side of the end wall 56 ofthe liner to provide a seal for the opening or hole 58. Septum 64 iscylindrical or disc-shaped and fits snugly within the passage 16 of thebody so that the periphery of said septum is in or is substantially incontact with the adjacent portion of the wall of said passage 16.

The septum 70 shown here is of the character shown and described in theMcKinney application for a Septum, Ser. No. 496,337, filed Oct. 15,1965. This septum has a relatively soft central layer or ply 71 and anouter, harder layer 73 at each side of the central layer. The materialof the central layer of the septum is a soft silicone rubber comprisingan unfilled compound 30:5 Shore A. The outer layers are hard red filledcompound 60:5 Shore A.

This septum has been found to be very effective and satisfactory but itis to be understood that the septum may be of other character and ofother material. However, the septum should have substantial thickness,as pointed out and described in the above mentioned application Ser. No.496,337.

Means is provided for retaining the septum, liner and vaporizing tube inposition within passage 16 of the body, said means comprising acylindrical member 76 which is termed the septum retainer. This septumretainer is slidable into and out of the outer end portion of thepassage 16 of the body but is close fitting within said passage.

There is means for y g the septum retainer and for urging Same r ly fthe passage 16 with a predetermined pressure, said means and the septumretainer comprisingwhat is termed herein a septum retainer assemblyWl'11Ch 1S indicated generally at .8-.

The retainer 76 has an axial passage 78 which is termed a needle guidepassage the outer end of which flares, as at 80, to facilitate insertionof a needle or the like into said guide passage 78.

The retainer is carried by an arm 84 adjacent the free end thereof therebeing an annular groove 86 adjacent the outer or rear end of said septumretainer there being a reduced diameter flange 88 at the rear end of theseptum retainer. Arm 84 has an opening 90 therethrough in which the rearportion of the retainer 76 is received. The longitudinal extent of thegroove 86 is greater than the thickness of the arm 84 and a springretainer is removably disposed in said groove at the outer side of thearm 84 between said arm and the flange 88, thereby securing the septumretainer 76 to the arm 84.

Arm 84 has a hole therein adjacent the opposite end thereof forreception of a reduced diameter externally threaded rear end portion 90of an arm supporting shaft 92, there being a shoulder 94 at the inner orforward end of said reduced diameter portion 90 against which said armis positioned. There is a cylindrical, externally knurled knob 96disposed on said portion 90 of the shaft 92, said knob being hollow andprovided with an inner or forward end wall 98 having an opening 99therethrough of larger diameter than the diameter of the reduceddiameter portion 90 and insulated therefrom by means of a pair ofoppositely arranged plastic washers 100 of larger diameter than theopening 99 in the wall 18 of the knob, said washers being of anysuitable plastic material such as nylon for example. Washers 100 haveaxial holes therethrough with an annular, axially extending flange 102thereabout, the external diameter of the flanges is such as to bereceived within the opening 99 in the forward end wall 98 of the knob.The combined length of the flanges 102 is less than the thickness of theknob wall 98 and there is a nut 104 on the reduced diameter portion 90of shaft 92 for securing the washers and knob on said reduced diameterportion 90. Thus the knob is insulated against heat from the shaft 90and the rest of the inlet assembly.

Means for operably supporting the shaft 92 comprises a pair of spacedrear and front blocks and 112 disposed between top and bottom plates 114and 116 and secured therebetween by screws 118 disposed in alignedopenings adjacent the corners of said plates and adjacent the ends ofsaid blocks, there being nuts 120 on said screws. Shaft 92 is slidablydisposed in aligned openings 93 provided therefore in said blocks 110and 112. The top and bottom plates have spaced openings therein adjacentthe side edges thereof, corresponding openings in the top and bottomplates being in axial alignment with each other, the openings indicatedat 123 in the lower plate being larger than the openings in the topplate for reception of stem portion 124 of supporting posts, indicatedgenerally at 126. Posts 126 have tapped bores, not shown, extendinglongitudinally upward end portions for reception of screws, describedhereinafter. At the lower ends of said posts are hexagonal, or othersuitably shaped, nut portions 128 to accommodate a wrench or other toolfor holding the posts 126 against rotation. The stems 124 of the posts126 do not touch the lower plate because of the size of the openings.The top plate rests on the upper ends of the stems 124'and there aretapped bores extending longitudinally into the stems 124 from the upperends thereof, said tapped bores registering with the intermediateopenings in the top plate and receive screws 130 which secure theretainer supporting structure to the posts 126.

There is a coil spring 134 disposed on the shaft 92 between the rear endblock 110 and a washer 136 held in operative position by a pin 138secured in a cross bore, not shown, provided therefor in the shaft 92,said spring being under compression and adapted to yieldingly resistrearward movement of said shaft 92. Since the spring is external it iscool.

When the septum retainer 76 is disposed in the rear end portion of thebore 16 of the body 14 spring 134 urges the lever 14 forwardly so thatthe forward free end of the septum retainer is pressed against theadjacent side of the septum 70 with a predetermined pressure. The septumis correspondingly urged against the adjacent rear end wall 56 of theliner 50 and since said end wall 56 rests against the adjacent end ofthe vaporizer tube 46 the latter is also urged forwardly against theshoulder 32 of the fitting 26. Thus the septum, liner and vaporizer tubeare securely held in place within the bore 16 of the body 14.

The pressure of the septum retainer 76 on the septum also compresses theseptum and causes it to expand radially so that the peripheral edge ofthe septum is forced outwardly into sealing engagement with the adjacentportion of the wall of bore 16, the central, softer layer of the septumbeing pressed radially outward into effective sealing engagement withthe adjacent wall portion of the bore 16.

There is means for heating the carrier fluid and sample, said meanscomprising an electric heater such as cartridge heater 140 disposed in agroove 142 provided therefor in the under side of the body 14 andsecured in said groove by a plate 144 having a plurality of holestherein for reception of screws 146, said screws extending upwardlythrough bores provided therefor in the body 14 and being screwed intotapped bores in the lower ends of the posts 126. Groove 142 is longerthan the cartridge heater and electric Wires 148 are received in saidgroove to supply electric current to said heater.

Preferably the inlet is attached to the chromatograph without the innerparts thereof, the column fitting being attached to the analyticalcolumn of chromatograph.

With the septum retainer swung out of the way the vaporizer tube is slidinto the bore 16 with the cross cut end toward the septum or rear end ofthe inlet. The for- Ward end of the vaporizer tube must be disposedwithin the bore 30, and seats easily and fully into this bore which is aprecision bore. Thereafter the liner 59 is inserted into the bore 16 ofthe body 14 and over the vaporizer tube. The septum is then insertedinto the rear or outer end of the bore 16 and the septum retainer pulledback by means of the heat insulated knob 96 and swung over the septum.The arm 84 positions the septum retainer in alignment with the bore 16and it is moved into said bore by the force of spring 134. The retainerthen is partially in the inlet bore resting freely on the septum withthe full spring force effective on the septum for compressing saidseptum and holding it together with the liner and vaporizer tube inoperative position. With this arrangement one spring holds the entireassembly in place and because the spring will yield there isaccommodation for temperature expansion.

Removal of the inner parts is efiected in reverse order, utilizing atool which has a small hook at the forward end and all of these partsare removable from the outer free end of the inlet.

It will be readily apparent that there is thus easy access to the innerparts which can be easily and quickly removed for cleaning of residue orthe like from the vaporizer tube or vaporizing chamber. Also, the septumcan be easily and quickly changed.

The heater 140 is supplied with electric current from a suitable sourcethrough the wires 148, a variable transformer or other suitable devicebeing used in the electric circuit to the heater.

A carrier fluid is supplied to the inlet by means of a conduit 150 froma source of such fluid under pressure, said conduit being connected tothe input fitting 22a. Helium or other suitable gas may be used as thecarrier fluid or gas.

The carrier gas passes from conduit 150 into the longitudinallyextending passage through the inlet fitting, into the annular inletchamber 64, thence into the annular 6 passage 54, through the notches60, into the vaporizer passage 48, through the bore 34 of the columnfitting 22 and into the column of the chromatograph.

Insertion of the needle, indicated at 151, of the sample handlingsyringe indicated at 153 in FIG. 2, is through the needle guide passage78 of the septum retainer. It is to be understood that the septumretainer has a slightly loose connection with the arm 84 and thereforethe guide passage will be automatically aligned with the opening 58 inthe end wall of the liner.

The needle is further inserted through the septum and into the adjacentend of the vaporizer tube, this procedure being effected withouthang-up. Insertion of the needle into the vaporizer tube can be veryshallow and when the needle has been inserted to the desired depth thesample is discharged therefrom into the passage 48 of said vaporizertube.

The septum is always under correct compression, just the right amount ofpressure being exerted by the spring 134. There is not so much pressureas to cause the needle to carry pieces of rubber into the flow passagebut enough pressure to provide an effective seal by the septum. Also,there is instantaneous sealing of the septum when the needle iswithdrawn by reason of the pressure on the septum and rapid and repeatedinsertions of the needle can be made.

It is to be noted that the hole 58 through the end wall 56 of the lineris very little larger than the diameter of the needle so that leakagethrough said hole is minimized or substantially eliminated. Further, theinside diameter of the passage 48 of the vaporizer tube is small so thatthe needle nearly fills said passage diametrically speak mg.

The concentric tube arrangement provides a flow geometry that isparticularly effective in eliminating or minimizing band spreading andenhancing desired separation.

The carrier gas is pre-heated by the heater 140, the gas stream having ahigh velocity through the flow path or passages of the inlet and thesample is injected into this flow path in the direction of fluid flow.

Because of the relatively large mass of aluminum body and the high heatconductivity thereof there is an even, uniform and quick distribution ofheat from the cartridge heater and cold spots are eliminated.

Since the vaporizer tube and liner, which may also be considered aclosed end tube, define the flow passages through the inlet and are ofinert glass, sensitive compounds or samples are protected from metalsurface decomposition. Thus the sample can only contact an inertmaterial.

The carrier gas flowing at a high velocity washes the septum area,restricts flash-back and passes cleanly through the vaporizer tube tothe column without band spreading voids and carries along the sampleinjected into the vaporizer tube passage 48.

As the carrier gas is pre-heated the sample injected into the vaporizertube is quickly vaporized. Due to the small septum area exposed to thefluid in the flow path through the opening 58 in the end wall of theliner and the needle disposed in said opening practically no vaporizedsample material contacts the septum. Also, due to the small crosssectional area of the passage 48 of the vaporizer tube and the presenceof the needle therein at the outer end back-up is minimized. Further,the sample flows smoothly and without turbulence and there is no deadvolume in the sample flow path.

For certain situations it is desirable to retain some part of a sampleto prevent column contamination and this can be effected by packing thepassage 48 in the vaporizer tube with absorbent, filtering or someselective reactive material. That is, the vaporizer tube may be packedwith column material for on-column injection or reactants for pre-columnchemistry.

For example, for analyzing alcohol in blood, the vaporizer tube could bepacked with glass wool to retain the blood solids while water andalcohol is vaporized and flushed into the chromatograph.

In FIG. 6 there is shown a vaporizing tube 46 with packing material 160in the passage 48 thereof.

As pointed out above, the inner parts may be easily and quickly removedfrom the body 14 for cleaning or replacement. Particularly the vaporizertube may be removed and cleaned While another tube is being used in theinstrument.

The invention and its attendant advantages will be understood from theforegoing description and it will be apparent that various changes maybe made in the form, construction and arrangement of the parts of theinvention without departing from the spirit and scope thereof orsacrificing its material advantages, the arrangement hereinbeforedescribed being merely by Way of example, and we do not wish to berestricted to the specific form or uses mentioned except as defined inthe accompanying claims, wherein various portions have been separatedfor clarity of reading and not for emphasis.

We claim:

1. In an inlet for analytical apparatus and the like:

(A) support means;

(B) a tubular inner operably supported by said support means, said linerhaving a passage extending longitudinally therein, there being a wall atone end with a relatively small instrument opening therethrough foroperable reception of a needle of a sample handling instrument;

(C) a vaporizer tube operably supported by said support means, at leasta portion of said vaporizer tube being disposed in the liner passage,said vaporizer tube having a longitudinallyextending passagetherethrough, the outside diameter of said vaporizer tube being ofsmaller diameter than the inside diameter of said liner to therebyprovide an annular fluid passage between the liner and the vaporizertube, the opening in the end wall of the liner being aligned with thepassage through the vaporizer tube, there being fluid communicationbetween the space between the liner and vaporizer tube at the end of theliner having the end wall; a

(D) and a septum operably disposed against the outer side of the endwall of the liner.

2. The invention defined by claim 1 wherein the support means comprisesa body having a bore therein in which the liner is operably disposedwith the vaporizer tube operably supported within the tube, the septumbeing disposed in the body bore.

3. The invention defined by claim 1 and including retaining means forpressing the septum against the end wall of the liner.

4. The invention defined by claim 3 wherein the liner, vaporizer tube,and the septum are removably held in operable position by the supportingmeans, the retaining means for pressing the septum against the end wallof the liner, vapoizing tube and septum being movable to a positionreleasing said liner, vaporizing tube and septum so that they may beremoved from the supporting means.

5. The invention defined by claim 1 wherein the liner and vaporizer tubeare of inactive material.

6. The invention defined by claim 1 wherein the liner, vaporizer tubeand septum are of inactive material.

7. The invention defined by claim 3 wherein the retaining meansresiliently presses the septum against the end wall of the liner.

8. The invention defined by claim 1 and including means for heating thesupport means and hence the liner and vaporizer tube.

9. An inlet for analytical apparatus and the like:

(A) a body having a bore therein;

(B) a tubular liner of inactive material operably disposed in said bore,said liner having a longitudinally extending passage therein and havingan outer end wall with a small opening therethrough for reception of asmall diameter part of a sample introducing instrument;

(C) a vaporizer tube having a longitudinally passage therethrough, thevaporizer tube being of smaller outside diameter than the insidediameter of the liner to provide space for the flow of fluidtherebetween, the outer end of said vaporizer tube having notch meanstherein and abutting against the end wall of the liner, said notch meansproviding fluid communication between the space between the vaporizertube and the liner and the interior of the liner, said vaporizer tubebeing open at both ends and the passage in said tube being aligned withthe opening in the outer end wall of the liner,

(D) and a septum disposed in said bore and against the end wall of theliner.

10. The invention defined by claim 9 including a septum retainer urgingthe septum against the end wall of the liner.

11. The invention defined by claim 10 wherein the septum retainer isresiliently urged against said septum, said septum retainer having aninstrument guide passage therethrough in alignment with the opening inthe end wall of the liner.

12. The invention defined by claim 11 wherein the septum retainer ispositioned in the bore when in the septum retaining position, butmovable to a release position out of said bore, said liner, vaporizertube and septum being removable from the bore in said body when saidseptum retainer is in said release position.

13. The invention defined by claim 9, wherein there is a fitting in theforward end of the bore in said body, said fitting having an axialrecess therein for reception of the forward end of the vaporizer tube,there being a shoulder at the forward end of said recess against whichthe forward end of said vaporizer tube abuts, said fitting having anoutlet passage from said recess, the liner being shorter than thevaporizer tube so that there is an annular chamber between the exteriorof the vaporizer tube and the adjacent wall portion of the bore, saidchamber being closed at the forward end by said fixture butcommunicating with the space between the inner surface of the liner walland the exterior surface of the vaporizer tube; there being means forconnecting said chamber with a source of fluid under pressure.

14. The invention defined by claim 11, wherein the outer end of theliner is spaced inwardly of the outer end of the bore in the body, andthe septum is disposed in said bore at the outer end of the liner andagainst the end wall of said liner, and the septum retainer includes acylindrical part slidable into the outer end of said bore and intoengagement with the outer side of the septum, the resilient pressure ofthe septum retainer on said septum serving to retain the septum, theliner and the vaporizer tube in operating position in said bore.

15. The invention defined by claim 11, wherein the instrument guidepassage and the opening in the end wall of the liner are of such sizethat the needle of a sample introducing instrument is operably andslidably receivable therein, the passage through the vaporizer tubebeing slightly larger than. the external diameter of said needle toprovide for the flow of fluid therebetween.

16. The invention defined by claim 9, including heater means for heatingsaid body.

17. The invention defined by claim 11, wherein the bore in the body iscylindrical and the septum is circular and fits snugly in said bore, theresilient pressure of the septum retainer on the septum urging theperiphery of said septum into sealing engagement with the adjacent wallportion of the bore as well as into sealing engagement with the end wallof the liner.

18. In an inlet for chromatographs and the like:

(A) an elongated body having a longitudinally extending passagetherethrough;

(B) a column fitting secured in one end of said passage,

said fitting having an axial bore extending forwardly from the inner endand from the forward end of which a reduced diameter fluid dischargebore extends;

(C) a vaporizer tube of inactive material, said tube being of smalleroutside diameter than the inside diameter of the passage through thebody, a forward end portion of said vaporizer tube being snugly receivedin the axial bore of said fitting, the outer end of said vaporizer tubebeing spaced rearwardly of the outer end of the passage through the bodyand having notch means therein;

(D) a liner of inactive material, said liner having a passage extendinglongitudinally therein, there being a wall at the outer end of saidpassage with a relatively small instrument axial opening therethrough,for reception of the needle of a sample handling instrument, the outsidediameter of the liner being such as to be snugly received in the passageof the body, the inside diameter of said liner being greater than theoutside diameter of the vaporizer tube and fitting over an outer endportion of said vaporizer tube to provide an annular chamber about thevaporizer tube having a fluid connect with the interior of saidvaporizer tube, there being an inlet into said annular chamber, theouter end of said liner being spaced inwardly of the outer end of thepassage through the body With the Wall at the outer end of said linerresting on the outer end of the vaporizer tube, the

opening in the end Wall of the liner registering with the passagethrough the vaporizer tube;

(E) a septum in the outer end portion of the body passage, said septumabutting the outer side of the liner end wall;

(F) a septum retainer slidable and removably received Within the outerend portion of the body passage, said retainer having a small axialguide bore for reception of a needle of a sample delivering instrument,said guide bore being aligned with the opening in the end wall of theliner;

(G) and resilient means for urging said retainer against the septum witha predetermined pressure.

19. The invention defined by claim 9 including means 15 for releasablyretaining the liner and the vaporizing tube in the bore of the body.

References Cited FOREIGN PATENTS 739,179 7/1966 Canada.

OTHER REFERENCES Beckman Instruments Inc.: bulletin 7032, pp. 10, 11.

25 RICHARD c. QUEISSER, Primary Examiner.

VICTOR I. TOTH, Assistant Examiner.

18. IN AN INLET FOR CHROMATOGRAPHS AND THE LIKE: (A) AN ELONGATED BODYHAVING A LONGITUDINALLY EXTENDING PASSAGE THERETHROUGH; (B) A COLUMNFITTING SECURED IN ONE END OF SAID PASSAGE, SAID FITTING HAVING AN AXIALBORE EXTENDING FORWARDLY FROM THE INNER END AND FROM THE FORWARD END OFWHICH A REDUCED DIAMETER FLUID DISCHARGE BORE EXTENDS; (C) A VAPORIZERTUBE TO INACTIVE MATERIAL, SAID TUBE BEING OF SMALLER OUTSIDE DIAMETERTHAN THE INSIDE DIAMETER OF THE PASSAGE THROUGH THE BODY, A FORWARD ENDPORTION OF SAID VAPORIZER TUBE BEING SNUGLY RECEIVED IN THE AXIAL BOREOF SAID FITTING, THE OUTER END OF SAID VAPORIZER TUBE BEING SPACEDREARWARDLY OF THE OUTER END OF THE PASSAGE THROUGH THE BODY AND HAVINGNOTCH MEANS THEREIN; (D) A LINER OF A INACTIVE MATERIAL, SAID LINERHAVING A PASSAGE EXTENDING LONGITUDINALLY THEREIN, THERE BEING A WALL ATTHE OUTER END OF SAID PASSAGE WITH A RELATIVELY SMALL INSTRUMENT AXIALOPENING THERETHROUGH, FOR RECEPTION OF THE NEEDLE OF A SAMPLE HANDLINGINSTRUMENT, THE OUTSIDE DIAMETER OF THE LINER BEING SUCH AS TO BE SNUGLYRECEIVED IN THE PASSAGE OF THE BODY, THE INSIDE DIAMETER OF SAID LINERBEING GREATER THAN THE OUTSIDE DIAMETER OF THE VAPORIZER TUBE ANDFITTING OVER AN OUTER END PORTION OF SAID VAPORIZER TUBE TO PROVIDE ANANNULAR CHAMBER ABOUT THE VAPORIZER TUBE HAVING FLUID CONNECT WITH THEINTERIOR OF SAIF VAPORIZER TUBE, THERE BEING AN INLET INTO SAID ANNULARCHAMBER, THE OUTER END OF SAID LINER BEING SPACED INWARDLY OF THE OUTEREND OF THE PASSAGE THROUGH THE BODY WITH THE WALL AT THE OUTER END OFSAID LINER RESTING ON THE OUTER END OF THE VAPORIZER TUBE, THE OPENINGIN THE END WALL OF THE LINER REGISTERING WITH THE PASSAGE THROUGH THEVAPORIZER TUBE; (E) A SEPTUM IN THE OUTER END PORTION OF THE BODYPASSAGE, SAID SEPTUM ABUTTING THE OUTER SIDE OF THE LINER END WALL; (F)A SPETUM RETAINER SLIDABLE AND REMOVABLY RECEIVED WITHIN THE OUTER ENDPORTION OF THE BODY PASSAGE. SAID RETAINER HAVING A SMALL AXIAL GUIDEBORE FOR RECEPTION OF A NEEDLE OF A SAMPLE DELIVERING INSTRUMENT, SAIDGUIDE BORE BEING ALIGNED WITH THE OPENING IN THE END WALL OF THE LINER;(G) AND RESILIENT MEANS FOR URGING SAID RETAINER AGAINST THE SEPTUM WITHA PREDETERMINED PRESSURE.